Door latch



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Filed Oct. 14, 1957 2,924,47s Doon LATCH George Wartian, Detroit, Mich., `assignorV to Wartian Lock Company, St.. Clair Shores, Mich., a corporation of Michigan Y Application October14, 1957, Serial No.v 690,100 1 Claim, (Cl. 292-224) This invention relates to a door latch and has particular reference to a new and improved bolt operating mechanism for a doorlatch.

A principal object ofthe invention is and improved door latch.

Another object of the invention is to provide a bolt operating mechanism for a door latch.

A further object of the invention is to provide a door latch particularly adapted for use on a metal storm door or screen door.

Another object of the invention is to provide a door latch which is linexpensive to manufacture and to install in a door.

Other and further objects of the invention will be apparent from the following description and claim and may be understood by reference to the accompanying drawings, of which there are two sheets, which by way of illustration show a preferred embodiment of the invention and what I now consider to be the best mode in which l have contemplated applying the principles of my invention. Other embodiments of the invention may be used without departing from the scope o-f the present invention as set forth in the appended claim.

In the drawings:

Fig. l is a horizontal sectional view through a door having the improved door latch applied thereto;

Fig. 2 is a side elevational view of the latch with parts broken away;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on line 4 4 of Fig. 2;

Fig. 5 is a View similar to Fig. 4 but showing the latch bolt in its retracted position;

Fig. 6 is an end elevational view of a part of the latch mechanism and taken substantially on line 6-46 of Fig. 2; and

Fig. 7 is a view similar to Fig. 6 showing the latch bolt in its retracted position.

In Fig. l the improved latch structure is illustrated as applied to a door 10 which may be a metal storm or screen door adapted to close against a door frame 12 having a latch bolt receiving recess 14 and a strike plate 16 applied thereto. The latch mechanism includes a casing 18 secured on the inner side '20 of the door 10 and a knob 22 mounted on the outer side of the door.

The casing 18 is hollow and has an open side which is closed by a cover plate 24. The casing has anges 26 receiving screws 28 which also pass through the cover plate 24 and are threaded into the inner side of the door for securing the casing 18 on the door. A latch bolt 30 is pivoted in the casing 1S by a pin 32. The latch bolt is swingable on a vertical axis into and out of the casing 118 through rectangular opening 34 at one side of the casing 18.

A handle 36 yis pivoted in the casing 1'8 by means of a pin 38 which is parallel to the pin 32 on which the latch bolt 30 is pivoted. The handle 36 includes an outer handle portion 40 and a hook-shaped inner end 42 which to. provide a new rained States Patent 0 2,924,478 Patented Feb. 9i, i860 ICC is engageable with the latch bolt for retracting the bolt into the casing to its unlatched position.

The latch bolt 30 is shown in Fig. 3 in its latched position and a spring 44 reacts between a shoulder 46 on the bolt 30 and the end wall 48 of the casing 18 to urge the latch bolt to its latched position. The bolt 30 has an integral projection `50 on its lower face. The projection 50) has a cam surface 52 which is engaged by the inner end 42 of the operating lever or handle. 36 so that when the handle portion 40 is swung in a clockwise direction and as viewed in Figs. l, 3, 4, and 5, the inner end 42 of the. handle will react against the cam surface 452 on the latch bolt to retract the bolt, as illustrated in Fig. 5. When the handle is released, the spring y44 will return the bolt 30 to its latched position and the handle will thereby be returned to its normal position.

The latch bolt maybe operated from the other side of the door by the [knob 22' which, as shown in Fig. l, is rotatable within a collar 60 formed on a mounting plate y62 which is secured to the outer side of the door by suitable screws. The knob 22 is secured against axial displacement by a washer 64 seated within a groove at the inner end of the shank `66 of the knob. A stem 68 is slidably but non-rotatably received within the knob 22 and to this end the outer end of the stem y68 may be squared and received within a square opening '70 in the knob 22.

At its inner end the stem 68 is provided with a head 'l2 extending into the casing 18. The stem 68 may be journaled in a collar 74 formed on the cover plate 24 and extending through an opening 76 on the inner side of the door. The head 72 of the stem 68 is illustrated in Figs. 6 and 7 and includes radially extending projections 78 on opposite sides of the axis of the stern and in a common plane which contains the axis of the stem.

The handle 36 is provided with a pair of integral lugs each of which is engaged by one of the cam surfaces 78 formed on the head 72 of the stem. The stem 68 may be rotated in either direction by the knob 22 and rotation of the stem will cause one of the cam surfaces 78 to engage the opposed lug `80 on the handle 36 to pivot the handle in a direction to retract the latch bolt 30, as illustrated in Fig. 7. When the knob is released, the spring `44 will return the bolt 30, the handle 36 and the knob 22 to their normal positions.

It will be noted that the stem `68 has a non-rotatable connection with the knob 22 but is otherwise unconnected to the knob. The head 72 of the stem is retained within the casing 1S by the cover plate 24 so that the entire latch structure, including the stem 68, may be applied from the inner side of the door. The knob 22 which is carried solely by the mounting plate 62 is then slid over the outer end of the stem and the mounting plate is then secured to the door to co-mplete the assembly.

The upper surface of the latch bolt 30 is provided with a locking lug 82 and a locking element 84 is pivoted on the upper wall of the casing 18 by a pin 86. The pin 86 carries a locking disk 88 within the casing 1S and a projection 90 on the disk 8S may be moved into and out of the path of movement of the locking lug 82 on the bolt 30. The projection 90 is shown in Fig. 3 in its unlocked position and may be swung to the dotted-line position indicated at 92 by rotating the locking element 84. The lock may also be used to lock the bolt 30 in its unlatched position by first retracting the bolt 30 and then turning the locking element 84 to its locked position in which it will be disposed in the path of the locking lug 82 on the bolt to prevent movement of the bolt.

It will be seen that the latch structure described herein is relatively simple in construction and easy to install on a door since it is only necessary to provide a single small opening through the door through which the stem 68 extends. Since the stem forms a part of the latch structure and is retained thereby, it is not necessaryy to secure the knob to the stem by the usual set screw and the knob can then be retained solely by its mounting plate which is applied to the outer side of the door.

While I have illustrated and described a preferred embodiment of my invention, it is understood that this is capable of modication, and I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claim.

I claim:

A door latch comprising a casing adapted to be mounted on one side of a door, a latch bolt pivoted in said casing for swinging movement into and out of said casing between unlatched and latched positions, a handle pivoted in said casing and extending therefrom, a projection on one face of said bolt, said handle having an inner end engageable with said projection upon pivoting of said handle to swing said bolt to its unlatched position, spring 20 means urging said bolt to its latched position, a rotatable -knob adapted to be mounted on the other side of the door,

a stem rotatable with said knob and projecting therefrom through said door and into said casing, said stem having a head within said casing provided with radially extending cam surfaces on opposite sides of the axis of said stern, said handle having a pair of integral lugs projecting therefrom, said lugs being disposed-on opposite sides of the axis of said stem and each lug having a surface extending radially of said axis and opposed to one of said cam surfaces on said head, said stem being rotatable in either direction by said knob'to engage the radial surface on one of said lugs by the opposed cam surface on said head and thereby effect pivoting of said handle in a direction to swing said bolt to unlatched position.

' References Cite'd in the lile of this patent UNITED STATES PATENTS 333,656 Mix et al Jan. 5, 1886 1,515,164 Norwood Nov. 11, 1924 FOREIGN PATENTS 187 Great Britain 1892 514,386 Great Britain Nov. 7, 1939 

